1. Field of the Invention
The present invention relates to a display device. More particularly, the present invention relates to a display device capable of reducing time of replacing the flexible printed circuit board (FPC) during rework of the display device.
2. Description of Related Art
Generally, the display device can be broadly classified into two types, namely cathode ray tube (CRT) display device and flat panel display device. As for the flat panel display device type, it can be further classified into several types such as liquid crystal display (LCD), plasma display panel (PDP), field emission display (FED) and the like.
The working principle of plasma display panel (PDP) can be described as follows. A PDP typically comprises two glass substrates a plurality of electrodes and noble gas, for example, Ne, Xe, He, Xe etc. The electrodes are disposed on these two glass substrates respectively to form a plurality of discharge cells. The noble gas filled between within the discharge cell is excited under high-voltage electric field and emits ultraviolet (UV) light, and the emitted UV light impinges onto a phosphor layer of discharge cells whereby a plurality of visible lights, such as red, green, and blue lights, are emitted from the phosphor layer. Thus, a color image comprising a mixture of three fundamental colors (red, green and blue) of the visible lights via drive circuit can be displayed. Because of the advantages of larger display size, wide-view angle, thinner, lighter and no ionizing radiation, the plasma display has become the mainstream of flat panel display and could gradually replace the conventional CRT display in the near future.
FIG. 1 is a schematic view of a conventional plasma display device. Referring to FIG. 1, the conventional display device 100 comprises a display panel 110, a back plate 120, a flexible printed circuit (FPC) board 140, a driving chip 150, a printed circuit board (PCB) 160 and a heat-sink member 170, wherein the display panel 110 has a peripheral circuit area 112, and the back plate 120 is fixed on the display panel 110. It should be noted that the dimension of the back plate 120 is designed to be larger than or equal to that of the display panel 110, and then the display device 100 can be assembled onto the housing of the final display product. Moreover, cement 130 is often used for tightly sticking the back plate 120 onto the display panel 110.
One end of the flexible printed circuit board 140 is electrically connected to the peripheral circuit area 112 of the display panel 110, and another end of the flexible printed circuit board 140 is electrically connected to the printed circuit board (PCB) 160. In addition, the display device 100 can be driven by the driving chip 150 which is electrically connected to the flexible printed circuit board 140 and the peripheral circuit area 112 of the display panel 110. The heat-sink member 170 is installed on the driving chip 150 for conducting the heat away from the driving chip 150, wherein the heat-sink member 170 is fixed on the back plate 120 using screws 180.
Noticeably, the electrical connection between the flexible printed circuit board 140 and the peripheral circuit area 112 of the display panel 110 is secured by sticking the flexible printed circuit board 140 onto the display panel 110 using thermal compression technique. However, in an abnormal conditions, such as presence of undesired objects in the electrodes of the peripheral circuit area 112 of the display panel 110 or the poor quality of the flexible printed circuit board 140, the flexible printed circuit board 140 may get damaged during the thermal compression process for electrically connecting the flexible printed circuit board 140 and the peripheral circuit area 112 of the of the display panel 110 and as a result the flexible printed circuit board 140 may malfunction and may even result in breakdown of display device 100.
However, despite breakdown of display device 100 is induced by the malfunction of the flexible printed circuit board 140, the display panel 110 may be in good condition and function well. Therefore, it would desirable to repair display device 100 in order to utilize the display panel 110. One remedy of repairing the breakdown of display device 100 could be replacing the flexible printed circuit board 140. The rework of the display device 100 for replacing the flexible printed circuit board 140 is described as follows. Because the dimension of the back plate 120 is equal or larger than that of the display panel 110, the peripheral circuit area 112 of the display panel 110 is usually covered by the back plate 120, therefore, the back plate 120 must be separated from the display panel 110 for implementing rework of the display device 100. First, the heat-sink member 170, the driving chip 150 and the flexible printed circuit board 140 are detached and separated. Next, the cement 130 is cut to separate the back plate 120 from the display panel 110, and then the residual cement 130 on the display panel 110 is removed by using a chemical agent. Next, the flexible printed circuit board 140 is replaced with a new flexible printed circuit board 140, which is then electrically connected to the peripheral circuit area 112 of the display panel 110 by utilizing thermal compression process. Thereafter, the back plate 120 is fixed onto the display panel 110 via the cement 130. Accordingly, the rework of the display device 100 (i.e. changing the flexible printed circuit board 140) is complicated, incur wastage of the materials (i.e. cement, the chemical agent and etc), involve heavy labor work and consume substantial amount of time. Therefore, the rework cost of the display device 100 is significant.